PURPOSE: We investigated in detail the correlation between structure and function in the macula, and whether optical coherence tomography (OCT)-measured macular structure could be used to simulate the visual field. MATERIALS AND METHODS: This study comprised 60 eyes of 34 patients with open angle glaucoma (Anderson-Patella classification). To assess macular function, reliable data from the Humphrey field analyzer (HFA, SITA-standard, 10-2 program) for threshold, total deviation (TD), and pattern deviation (PD) were used. To assess macular structure, thickness data for the retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), and ganglion cell layer plus inner plexiform layer (GCL + IPL) from macular OCT maps (3D OCT-2000, Topcon) were analyzed. Spearman's coefficient of correlation analysis was performed to determine the significance of the correlation, as well as the formula for simulation. The formula was used to calculate the simulated threshold, TD, and PD values. The simulation method was validated by comparing results for simulated and actual visual fields in a new data set of 29 eyes from glaucoma patients. RESULTS: In most test points, macular function and the layer-by-layer structure were significantly correlated, however, the distribution of highly-correlated points varied. Simulated grayscale maps of the visual field based on the formula of regression line for RNFLT and thresholds were similar to actual visual fields. There was a significant correlation between simulated visual fields created from RNFLT, GCC and GCL + IPL data and actual average threshold values in all 68 test points (r = 0.63-0.87, p < 0.001) and TD (r = 0.62-0.86, p < 0.001). CONCLUSION: We found that there was a significant correlation between structure and function in the macular area, and that simulated visual fields from RNFLT data reflected actual visual fields. Such a simulation of macular function from OCT parameters may be useful in assessing glaucoma in patients who have difficulty undergoing actual visual field examinations.

PURPOSE: The purpose of this study was to investigate biologically meaningful endotypes of open-angle glaucoma (OAG) by applying unsupervised machine learning to plasma metabolites. METHODS: This retrospective longitudinal cohort study enrolled consecutive patients aged ≥20 years with OAG at Tohoku University Hospital from January 2017 to January 2020. OAG was confirmed based on comprehensive ophthalmic examinations. Among the 523 patients with OAG with available clinical metabolomic data, 173 patients were longitudinally followed up for ≥2 years, with available data from ≥5 reliable visual field (VF) tests without glaucoma surgery. We collected fasting blood samples and clinical data at enrollment and nuclear magnetic resonance spectroscopy to profile 45 plasma metabolites in a targeted approach. After computing a distance matrix of preprocessed metabolites with Pearson distance, gap statistics determined the optimal number of OAG endotypes. Its risk factors, clinical presentations, metabolomic profiles, and progression rate of sector-based VF loss were compared across endotypes. RESULTS: Five distinct OAG endotypes were identified. The highest-risk endotype (endotype B) showed a significant faster progression of central VF loss (P = 0.007). Compared with patients with other endotypes, those with endotype B were more likely to have a high prevalence of dyslipidemia, cold extremities, oxidative stress, and low OAG genetic risk scores. Pathway analysis of metabolomic profiles implicated altered fatty acid and ketone body metabolism in this endotype, with 34 differentially enriched pathways (false discovery rate [FDR] < 0.05). CONCLUSIONS: Integrated metabolomic profiles identified five distinct etiologic endotypes of OAG, suggesting pathological mechanisms related with a high-risk group of central vision loss progression in the Japanese population.

Corneal hysteresis (CH) is associated with glaucomatous structural changes. We retrospectively investigated the association between CH and the regional circumpapillary retinal nerve fibre layer thickness (cpRNFLT) in 419 eyes of 419 patients with normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG). CH was used as the explanatory variable, and cpRNFLT (total and quadrant) was used as the dependent variable. Standardized β coefficients were compared both overall and between the NTG and POAG groups. Multiple regression analysis with CH as the explanatory variable and cpRNFLT parameters as the dependent variables suggested that even after adjusting for age, sex, intraocular pressure (IOP), axial length, and central corneal thickness, all areas of the cpRNFLT were significantly associated with CH, except for the nasal quadrant. In the stratified analysis by glaucoma type, a positive relationship between CH and regional cpRNFLT tended to be maintained in the NTG group but not in the POAG group (P = 0.060 for interaction). Additionally, in the NTG group, the CH-inferior cpRNFLT relationship was particularly strong in the less-IOP fluctuation group. These results suggest that CH may be a potential predictor of anatomical vulnerability around the optic nerve, particularly enhancing the inferior regions of NTG.

In this study, we aimed to investigate the effects of the deficient antioxidative gene, nuclear factor-erythroid 2-related factor 2 (Nrf2), on 17β-estradiol (E2)-mediated oxidative stress response, with a specific focus on growth factor production and cell death in Müller cells and retinal tissue. Administration of hydrogen peroxide (H2O2) reduced the viability of Müller cells derived from Nrf2 wild-type (WT) and knockout (KO) mice. However, this effect was more significant in the KO cells than in the WT cells. Pretreatment with E2 inhibited H2O2-induced cell death in both Nrf2 WT and KO Müller cell genotypes. Small interfering RNA-mediated gene silencing of estrogen receptor 2 (Esr2) attenuated the cell survival-promoting activity of E2 in Nrf2 KO Müller cells, while other identified estrogen receptors, Esr1 or G protein-coupled estrogen receptor 1 (Gper1), had no effect. Western blotting revealed higher ESR2 expression levels in Nrf2 KO cells than in WT Müller cells. Conditioned media from E2-and H2O2-treated Nrf2 WT or KO Müller cells enhanced the dissociated retinal cell viability compared with H2O2-treated cells. Both quantitative reverse-transcription polymerase chain reaction assay (qRT-PCR) and enzyme-linked immunosorbent assay exhibited a significant increase in fibroblast growth factor 2 (FGF2) expression levels in E2-and H2O2-treated Nrf2 WT and KO Müller cells compared to those in E2-treated cells. In vivo, administration of N-methyl-N-nitrosourea (MNU) reduced the thickness and cell density of the outer nuclear layer (ONL) in Nrf2 KO mice and enhanced the number of terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells in the ONL. However, E2 administration attenuated these defects in MNU-treated mice. Concomitant administration of MNU and E2 enhanced FGF2 protein levels in retinal lysates of Nrf2 KO mice. In conclusion, E2 demonstrated a significant role in preventing oxidative stress-induced retinal cell death by stimulating FGF2 production in Müller cells, independent of the Nrf2 gene. Based on these findings, we anticipate that exogenous administration of estrogens or ESR2-selective agonists could aid in treating patients with oxidative stress-related retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa.

PURPOSE: To compare blood flow (BF) impairment patterns in different optic neuropathies using laser speckle flowgraphy (LSFG). METHODS: This retrospective study enrolled 24 eyes of 24 patients with non-arteritic anterior ischemic optic neuropathy (NAAION), 59 eyes of 59 patients with optic neuritis (ON), 677 eyes of 677 patients with open-angle glaucoma (OAG), and 110 eyes of 110 controls. The patient backgrounds of all groups were compared. Ophthalmologic findings were evaluated, adjusting for age, sex, blood pressure, pulse rate, and underlying systemic diseases with 1:1 optimal propensity score matching. We used LSFG to obtain optic nerve head (ONH) vessel-area mean blur rate (MBR; ONH-MV), ONH tissue-area MBR (ONH-MT), and choroidal MBR. The NAAION and ON groups were compared with the control and OAG groups. RESULTS: Best-corrected visual acuity was worse in the NAAION, ON, and OAG groups than in controls (p < 0.001). Circumpapillary retinal nerve fibre layer thickness was higher in the NAAION and ON groups and lower in the OAG group than in controls (p < 0.001). Compared to controls, the NAAION and OAG groups had significantly lower ONH-MV, ONH-MT, and choroidal MBR (p < 0.05). Additionally, the NAAION group had lower ONH-MV and choroidal MBR than the OAG group (p = 0.003 and p < 0.001, respectively) but no difference in ONH-MT (p = 0.857). The ON group had significantly lower ONH-MV and choroidal MBR compared to the controls (p < 0.001 and p = 0.022, respectively) but no difference in ONH-MT (p = 0.773). CONCLUSION: Optic neuropathies showed different patterns of ocular BF impairment. Therefore, LSFG can be a useful tool for differentiating optic neuropathies.

PURPOSE: We assess long-term surgical outcomes after an initial trabeculectomy for cytomegalovirus-associated anterior uveitis with secondary glaucoma (CMV-SG). METHODS: We retrospectively reviewed the medical records of 16 eyes of 15 patients with CMV-SG and 157 eyes of 157 patients with primary open-angle glaucoma. The average follow-up period was approximately 3 years. Surgical success was defined as intraocular pressure (IOP) below 18 mmHg and at least 20% lower than baseline. RESULTS: Kaplan-Meier survival analysis revealed that bleb survival rates were not significantly different in the CMV-SG and POAG groups (P = 0.75). Bullous keratopathy occurred in 2 of 16 eyes with CMV-SG postoperatively but did not occur in the POAG group. The corneal endothelial cell density decreased by 34.2 ± 22.7% in the CMV-SG group during an average follow-up period of 2.7 ± 2.0 years. CONCLUSION: Trabeculectomy effectively controlled IOP in CMV-SG, but attention must be paid to corneal endothelial cell loss.

PURPOSE: Equol is metabolized by intestinal bacteria from soy isoflavones and is chemically similar to estrogen. Dietary habits, such as consumption of soy products, influence equol production. A relationship between glaucoma and estrogen has been identified; here, we investigated the relationship between equol production status and glaucoma in Japan. METHODS: We recruited 68 normal-tension glaucoma (NTG) patients (male to female ratio 26:42, average age 63.0 ± 7.6 years) and 31 controls (male to female ratio 13:18, average age 66.0 ± 6.3 years) from our hospital. All women included were postmenopausal. Urinary equol concentration was quantified with the ELISA method. MD was calculated based on the Humphrey visual field. The association between MD and equol was analyzed with Spearman's rank correlation coefficient. The Mann-Whitney U test was used to compare the equol-producing (> 1 μM) and non-producing (< 1 μM) subjects. We also investigated the association between equol and glaucoma with a logistic regression analysis. RESULTS: There was a significant association between equol and MD (r = 0.36, P < 0.01) in the NTG patients. Glaucoma, represented by MD, was significantly milder in the equol-producing subjects than the non-equol producing subjects (P = 0.03). A multivariate analysis revealed the independent contributions of equol, cpRNFLT, and IOP to MD (P = 0.03, P = 0.04, and P < 0.01, respectively). CONCLUSION: Our results suggest that equol, acting through estrogen receptor-mediated neuroprotective effects, might be involved in suppressing the progression of NTG. This result also adds to evidence that glaucoma may be influenced by lifestyle.

PURPOSE: To investigate sectoral differences in the relationship between intraocular pressure (IOP) dynamics during dark-room prone testing (DRPT) and visual field (VF) defect progression in primary open-angle glaucoma (POAG) patients. DESIGN: Retrospective, longitudinal study PARTICIPANTS: This retrospective study included 116 eyes of 84 POAG patients who underwent DRPT and had at least five reliable VF tests conducted over a more than two-year follow-up period. We excluded eyes with mean deviation worse than -20 dB or a history of intraocular surgery or laser treatment. METHODS: Average total deviation (TD) was calculated in the superior, central, and inferior sectors of the Humphrey 24-2 or 30-2 program. During DRPT, IOP was measured in the sitting position, and after 60 minutes in the prone position in a dark room, IOP was measured again. The relationship between IOP change during DRPT, IOP after DRPT, and TD slope in each quadrant was analyzed with a linear mixed-effects model, adjusting for other potential confounding factors. MAIN OUTCOME MEASURES: TD slope in each quadrant, IOP change during DRPT, and IOP after DRPT RESULTS: IOP after DRPT and IOP change during DRPT were 18.16±3.42 mmHg and 4.92±3.12 mmHg, respectively. Superior TD slope was significantly associated with both IOP after DRPT (β=-0.28, p=0.003) and IOP change during DRPT (β=-0.21, p=0.029), while central (β=-0.05, p=0.595; β=-0.05; p=0.622) and inferior (β=0.05, p=0.611; β=0.01, p=0.938) TD slopes were not. CONCLUSION: DRPT might be a useful test to predict the risk of superior VF defect progression in eyes with POAG.

PURPOSE: Timely detection and treatment of visual impairments and age-related eye diseases are essential for maintaining a longer, healthier life. However, the shortage of appropriate medical equipment often impedes early detection. We have developed a portable self-imaging slit-light device utilizing NIR light and a scanning mirror. The objective of our study is to assess the accuracy and compare the performance of our device with conventional nonportable slit-lamp microscopes and anterior segment optical coherence tomography (AS-OCT) for screening and remotely diagnosing eye diseases, such as cataracts and glaucoma, outside of an eye clinic. APPROACH: The NIR light provides an advantage as measurements are nonmydriatic and less traumatic for patients. A cross-sectional study involving Japanese adults was conducted. Cataract evaluation was performed using photographs captured by the device. Van-Herick grading was assessed by the ratio of peripheral anterior chamber depth to peripheral corneal thickness, in addition to the iridocorneal angle using Image J software. RESULTS: The correlation coefficient between values obtained by AS-OCT, and our fabricated portable scanning slit-light device was notably high. The results indicate that our portable device is equally reliable as the conventional nonportable slit-lamp microscope and AS-OCT for screening and evaluating eye diseases. CONCLUSIONS: Our fabricated device matches the functionality of the traditional slit lamp, offering a cost-effective and portable solution. Ideal for remote locations, healthcare facilities, or areas affected by disasters, our scanning slit-light device can provide easy access to initial eye examinations and supports digital eye healthcare initiatives.

PURPOSE: To investigate the relationship between the dynamics of intraocular pressure (IOP) during dark-room prone testing (DRPT) and IOP over a relatively long-term follow-up period. METHODS: This retrospective study enrolled 84 eyes of 51 primary open-angle glaucoma patients who underwent DRPT for whom at least three IOP measurements made using Goldmann applanation tonometry were available over a maximum follow-up period of two years. We excluded eyes with a history of intraocular surgery or laser treatment and those with changes in topical anti-glaucoma medication during the follow-up period. In DRPT, IOP was measured in the sitting position, and after 60 min in the prone position in a dark room, IOP was measured again. In this study, IOP fluctuation refers to the standard deviation (SD) of IOP, and IOP max indicates the maximum value of IOP during the follow-up. The relationship between these parameters was analyzed with a linear mixed-effects model, adjusting for clinical parameters including age, gender, and axial length. RESULTS: IOP increased after DRPT with a mean of 6.13 ± 3.55 mmHg. IOP max was significantly associated with IOP after DRPT (β = 0.38; p < 0.001). IOP fluctuation was significantly associated with IOP change in DRPT (β = 0.29; p = 0.007). CONCLUSION: Our findings suggest that short-term and relatively long-term IOP dynamics are associated. Long-term IOP dynamics can be predicted by DRPT to some extent.

INTRODUCTION: Our study was conducted to determine factors associated with the effectiveness of a β-blocker eye drop add-on in altering pulse rate (PR) in glaucoma patients. METHODS: This retrospective study examined 236 eyes of 138 patients who received a β-blocker eye drop add-on during follow-up. Patients were included if at least one PR measurement was available both before and after the add-on was started. We collected data on ophthalmic parameters: longitudinal PR; longitudinal choroidal blood flow, represented by laser speckle flowgraphy-measured mean blur rate (MBR); and diacron-reactive oxygen metabolites (d-ROMs). We used a multivariable linear mixed-effects model to investigate the effectiveness of the β-blocker eye drop add-on in altering PR and examined factors contributing to a larger PR alteration after the add-on was started by analyzing the effect on PR of the interaction term between the add-on and clinical factors. We used the k-means method to classify the patients. RESULTS: The β-blocker eye drop add-on reduced PR (- 7.61 bpm, P < 0.001). Female gender, higher PR when the add-on was started, lower central corneal thickness, and a higher d-ROM level were associated with greater reduction in PR (P < 0.05). In a cluster of patients with these clinical features, choroidal MBR increased by + 3.42% when we adjusted for change over time; MD slope, which represents the speed of glaucoma progression, improved by + 0.64 dB/year (P < 0.05). CONCLUSIONS: We identified a glaucoma subgroup in which PR decreased, choroidal blood flow increased, and glaucoma progression slowed after a β-blocker eye drop add-on was started.

PURPOSE: To investigate clinical factors associated with foveal avascular zone (FAZ) parameters obtained using OCT angiography (OCTA) with assistance from a previously developed artificial intelligence (AI) platform in eyes with open-angle glaucoma (OAG). DESIGN: Retrospective longitudinal. PARTICIPANTS: This study followed up 885 eyes of 558 patients with OAG for ≥ 2 years; all eyes underwent ≥ 5 Humphrey visual-field (VF) tests and had 3.0 × 3.0 mm macular OCTA scans available. METHODS: Average total deviation (TD) in the superior, superocentral, inferocentral, and inferior sectors of the Humphrey 24-2 program was calculated. We collected 3.0 × 3.0 mm macular OCTA images from each patient and used a previously developed AI platform with these images to obtain FAZ parameters, including FAZ area, FAZ circularity index (CI), and FAZ perimeter. Multivariable linear mixed-effects models were used to analyze the relationship between FAZ parameters, TD or TD slope in each quadrant, and systemic factors, adjusting for potential confounding factors, including axial length. MAIN OUTCOME MEASURES: Ophthalmic and systemic variables, FAZ parameters, and TD or TD slope in each quadrant. RESULTS: The multivariable model showed that FAZ parameters were correlated with both TD and TD slope in the inferocentral quadrant (β = -0.244 - 0.168, P < 0.001). Both upper-half and lower-half FAZ parameters were better associated with TD-inferocentral and TD-inferocentral slope than TD-superocentral or TD-superocentral slope in terms of β size and statistical significance, indicating that there was no evident vertical anatomical correspondence between TD in the central quadrant and FAZ parameters. Foveal avascular zone area enlargement was associated with female gender (β = 0.242, P = 0.003). Loss of FAZ circularity was associated with both aging and comorbid sleep apnea syndrome (SAS) (yes: 1, no: 0) (β = -0.188, P < 0.001; β = -0.261, P = 0.031, respectively). Foveal avascular zone perimeter elongation was associated with aging and female gender (β = 0.084, P = 0.040; β = 0.168, P = 0.042, respectively). CONCLUSIONS: Artificial intelligence-assisted OCTA-measured FAZ enlargement and irregular shape might be good markers of ocular hypoperfusion and associated inferocentral VF defect progression in eyes with OAG. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Glaucoma is a leading cause of blindness worldwide in older people. Profiling the aqueous humor, including the metabolites it contains, is useful to understand physiological and pathological conditions in the eye. In the current study, we used mass spectrometry (MS) to characterize the aqueous humor metabolomic profile and biological features of patients with glaucoma. Aqueous humor samples were collected during trabeculectomy surgery or cataract surgery and analyzed with global metabolomics. We included 40 patients with glaucoma (32 with POAG, 8 with NTG) and 37 control subjects in a discovery study. VIP analysis revealed five metabolites that were elevated and three metabolites that were reduced in the glaucoma patients. The identified metabolomic profile had an area under the receiver operating characteristic curve of 0.953. Among eight selected metabolites, the glutathione level was significantly decreased in association with visual field defects. Moreover, in a validation study to confirm the reproducibility of our findings, the glutathione level was reduced in NTG and POAG patients compared with a cataract control group. Our findings demonstrate that aqueous humor profiling can help to diagnose glaucoma and that various aqueous humor metabolites are correlated with clinical parameters in glaucoma patients. In addition, glutathione is clearly reduced in the aqueous humor of glaucoma patients with both IOP-dependent and IOP-independent disease subtypes. These findings indicate that antioxidant agents in the aqueous humor reflect glaucomatous optic nerve damage and that excessive oxidative stress may be involved in the pathogenesis of glaucoma.

AIMS: To evaluate differences in systemic BDNF levels between primary open-angle glaucoma (POAG) patients and normal-tension glaucoma (NTG) patients. METHODS: This study collected blood samples from 260 NTG patients, 220 age-matched POAG patients, and 120 age-matched cataract patients (as controls). BDNF levels were measured with an antibody-conjugated bead assay system (Luminex). RESULTS: We found that plasma BDNF levels in the NTG group were significantly lower than in the POAG and cataract control groups. There was no significant difference between the POAG and cataract groups. CONCLUSION: This result suggests that a low level of systemic BDNF may contribute to the pathogenesis of glaucoma in an IOP-independent manner.

We aimed to investigate the impact of glutathione trisulfide (GSSSG) on lipopolysaccharide (LPS)-induced inflammation in retinal glia. Inflammatory responses in mouse-derived glial cells and Wistar rat retinas were stimulated with administration of LPS. Cell survival and proinflammatory cytokine production were examined using the Calcein-AM assay, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Retinal microglia were visualized with immunohistochemistry for Iba1. Administration of LPS (10 µg/mL) or GSSSG (less than 100 µM) did not affect survival of cultured primary Müller cells and established microglial cells (BV-2). RT-qPCR and ELISA indicated that GSSSG inhibited LPS-induced gene upregulation and protein secretion of proinflammatory cytokines in these glial cells and rat retinas. GSSSG inhibited LPS-induced activation of TGF-β-activated kinase 1 (TAK1), which is an upstream kinase of NF-κB, in BV-2 cells. Finally, in vivo experiments indicated that intravitreal administration of GSSSG but not its relative glutathione disulfide (GSSG) inhibited LPS (500 ng)-induced accumulation of Iba1-immunopositive microglia in rat retinas. Taken together, GSSSG has the potential to prevent pathogenesis of inflammation-associated ocular diseases by inhibiting proinflammatory cytokine expression in retinal glial cells.

PURPOSE: To investigate the association between ocular/systemic factors and visual acuity decline in glaucoma patients with loss of ganglion cell complex thickness (GCCT). METHODS: In 515 eyes of 515 patients with open-angle glaucoma (mean age, 62.6 ± 12.8 years; mean deviation, -10.95 ± 9.07 dB), we used swept-source optical coherence tomography to measure macular GCCT in sectors classified as corresponding to circumpapillary retinal nerve fiber layer clock-hour sectors from 7 o'clock (inferotemporal) to 11 o'clock (superotemporal). We calculated Spearman's rank correlation coefficient between each sector and best-corrected visual acuity (BCVA), determined cutoff values for BCVA decline (<20/25), and used multivariable linear regression models to determine the correlation between BCVA and biological antioxidant potential (BAP), corneal hysteresis (CH), and temporal-tissue optic nerve head blood flow (represented by temporal mean blur rate, or MBR-T). RESULTS: Macular GCCT corresponding to the 9 o'clock sector had the highest correlation with BCVA (Rs = -0.454; P < 0.001) and a cutoff of 76.17 µm (area under the receiver operating characteristic curve = 0.891; P < 0.001). Subjects below this cutoff (N = 173) showed significant correlations between BCVA and age, BAP, CH, and MBR-T (β = 0.192, P = 0.033; β = -0.186, P = 0.028; β = -0.217, P = 0.011; and β = -0.222, P = 0.010, respectively). CONCLUSIONS: Multiple factors are involved in BCVA decline in patients with glaucoma with decreased macular GCCT. This suggests that evaluating BCVA may require assessing multiple factors. TRANSLATIONAL RELEVANCE: Multiple factors contribute to BCVA decline.

PURPOSE: This study investigated the effect of dipeptidyl peptidase-4 inhibitors (DPP-4is) on fibrosis after glaucoma filtering surgery with clinical data and an in vitro model that used transforming growth factor-β (TGF-β) to induce human Tenon's fibroblast (HTF) fibrosis. METHODS: The medical records of 41 eyes of 35 patients with diabetes with neovascular glaucoma (NVG) who received initial trabeculectomy were retrospectively reviewed. The surgical success rate was compared between cases that received (n = 23) and did not receive (n = 18) DPP-4i treatment for diabetes. The antifibrotic effects of linagliptin (a DPP-4i) were evaluated with quantitative real-time PCR for fibrosis markers (α-smooth muscle actin, collagen Iα, and fibronectin), a scratch assay, and a collagen gel contraction assay of primary cultured HTFs treated with TGF-β1 and linagliptin. Western blotting analysis was performed to evaluate the levels of phosphorylated Smad2 and Smad3 in the presence of linagliptin. RESULTS: The Kaplan-Meier curve for bleb survival was higher in patients who received DPP-4is (P = 0.017, log-rank test). The in vitro experiments demonstrated that treatment with linagliptin attenuated the elevated levels of fibrosis markers induced by TGF-β1 in HTFs. Linagliptin treatment also prevented the migration and gel contraction of HTFs. Linagliptin inhibited the phosphorylation of Smad2 and Smad3, which is the canonical pathway of TGF-β signaling. CONCLUSIONS: The current study indicates the potential effect of DPP-4is for maintaining bleb function after glaucoma filtering surgery in patients with diabetes with NVG. Our results demonstrate that linagliptin attenuates fibrotic change in HTFs by inhibiting TGF-β/Smad signaling.

INTRODUCTION: Paget's disease of bone (PDB) is a skeletal disorder characterized by disorganized bone remodeling due to abnormal osteoclasts. Tumor necrosis factor receptor superfamily member 11A (TNFRSF11A) gene encodes the receptor activator of nuclear factor kappa B (RANK), which has a critical role in osteoclast function. There are five types of rare PDB and related osteolytic disorders due to TNFRSF11A tandem duplication variants so far, including familial expansile osteolysis (84dup18), expansile skeletal hyperphosphatasia (84dup15), early-onset familial PDB (77dup27), juvenile PDB (87dup15), and panostotic expansile bone disease (90dup12). MATERIALS AND METHODS: We reviewed a Japanese family with PDB, and performed whole-genome sequencing to identify a causative variant. RESULTS: This family had bone symptoms, hyperphosphatasia, hearing loss, tooth loss, and ocular manifestations such as angioid streaks or early-onset glaucoma. We identified a novel duplication variant of TNFRSF11A (72dup27). Angioid streaks were recognized in Juvenile Paget's disease due to loss-of-function variants in the gene TNFRSF11B, and thought to be specific for this disease. However, the novel recognition of angioid streaks in our family raised the possibility of occurrence even in bone disorders due to TNFRSF11A duplication variants and the association of RANKL-RANK signal pathway as the pathogenesis. Glaucoma has conversely not been reported in any case of Paget's disease. It is not certain whether glaucoma is coincidental or specific for PDB with 72dup27. CONCLUSION: Our new findings might suggest a broad spectrum of phenotypes in bone disorders with TNFRSF11A duplication variants.

Oxidative stress-induced damage is an underlying mechanism in the pathogenesis of age-related retinal diseases. Here, we examined the effects of K560, a potential candidate drug for the treatment of these diseases, on oxidative stress-induced retinal cell death. K560 is a novel isozyme-specific inhibitor of histone deacetylase 1 and 2 (HDAC1/2). Histone acetylation in retinal lysates and dissociated retinal cells was detected with a western blot analysis and cell-based enzyme-linked immunosorbent assay (ELISA), respectively. The viability of mouse retinal cells was measured with an alamarBlue assay. We used immunohistochemistry for RNA binding protein with multiple splicing (RBPMS) to visualize the retinal ganglion cells (RGCs) of mice. A ELISA analysis indicated that histone acetylation was enhanced in dissociated mouse retinal cells tretaed with K560. The cell viability assay indicated that K560 attenuated both exogenous hydrogen peroxide-induced and endogenous oxidative stress-induced cell death in dissociated retinal cells. Western blot analysis indicated that intravitreal K560 administration enhanced the acetylation of histones H3 and H4 in mouse retinal lysates. To examine the effect of K560 on oxidative stress-induced RGC death, we performed whole-mount immunohistochemistry for RBPMS for retinas dissected from eyes treated with K560 or vehicle on day one, and K560 or vehicle and NMDA on day two. Quantification of RBPMS-immunopositive cells indicated that K560 attenuated NMDA-induced RGC death. Taken together, our findings suggest that administration of a HDAC1/2-specific inhibitor, i.e., K560, may be effective in the treatment of oxidative stress-mediated retinal degeneration and have less cytotoxicity than other known HDAC inhibitors, which are known to target a wide range of HDAC family members.

PURPOSE: To investigate the association of systemic oxidative stress markers and optic nerve head (ONH) blood flow in normal-tension glaucoma (NTG) patients, as well as sex differences in this association. METHODS: This was a cross-sectional study of 235 eyes with NTG of 134 patients (56 male, 78 female; mean age, 60.9±14.1 years). Laser speckle flowgraphy (LSFG) was used to measure ONH blood flow (mean blur rate in the tissue area of the ONH; MBR-T) and LSFG pulse-waveform parameters, including flow acceleration index in the tissue area of the ONH (FAI-T). Oxidative stress markers, diacron-reactive oxygen metabolites (d-ROMs), and biological antioxidant potential (BAP) were measured with a free radical elective evaluator. Spearman's rank correlation test and a multivariate linear mixed-effect model were used to investigate factors associated with ONH blood flow. RESULTS: MBR-T was significantly correlated with age (rs = -0.28, p < 0.001), mean arterial pressure (rs = -0.20, p = 0.002), intraocular pressure (rs = 0.24, p < 0.001), peripapillary retinal nerve fiber layer thickness (rs = 0.62, p < 0.001), and disc area (rs = -0.26, p < 0.001), but not with serum d-ROM level. Separate analyses of the subjects divided by sex showed that BAP was positively correlated to MBR-T (rs = 0.21, p = 0.036) and FAI-T (rs = 0.36, p < 0.001) only in male subjects. Similarly, BAP was significantly associated with MBR-T (β = 0.25, p = 0.026) and FAI-T (β = 0.37, p < 0.001) in male subjects in a multivariate linear mixed-effect model. CONCLUSION: A lower serum antioxidant level, as indicated by BAP, was associated with reduced ONH blood flow only in male NTG patients. Our findings suggest that there are sex differences in the involvement of oxidative stress in the pathogenesis of reduced ocular blood flow in NTG.

Glaucoma is one of the most common causes of blindness worldwide. It is thought to be a multifactorial disease with underlying mechanisms that include mitochondrial dysfunction and oxidative stress. Here, we used NF-E2 related factor 2 (Nrf2) knockout (KO) mice, which are vulnerable to oxidative stress, to examine a neuroprotective effect against oxidative stress due to rotenone, a mitochondrial complex I inhibitor. Wild-type (WT) and Nrf2 KO mice received an oral solution of rotenone for 30 days. We then extracted the retinas and performed immunohistochemistry and quantitative RT-PCR. We also prepared a primary Müller cell culture of samples from each mouse, added 30 μM rotenone, and then measured cell viability, cytotoxicity and CellRox absorbance. We also examined gene expression. We found a significant increase in the number of 8-OHdG-positive retinal ganglion cells (RGCs) after rotenone administration in both the WT and Nrf2 KO mice. There was no difference in the number of RNA-binding protein with multiple splicing (RBPMS)-positive RGCs in the WT and Nrf2 KO mice, but Nrf2 KO mice that were given rotenone had significantly less retinal gene expression of RBPMS than Nrf2 KO mice given a control. Moreover, there was significantly higher mRNA gene expression of vimentin and glial fibrillary acidic protein (GFAP) in Nrf2 KO mice that received rotenone than WT mice that received rotenone. A statistical analysis of the in vitro experiment showed that cell viability was lower, cytotoxicity was higher, and oxidative stress was higher in the Müller cells of the Nrf2 KO mice than the WT mice. Finally, brain-derived neurotrophic factor (BDNF) and basic fibroblast growth factor (bFGF) were significantly higher in the Müller cells of the Nrf2 KO mice than the WT mice. These findings suggest that in Nrf2 KO mice under oxidative stress caused by rotenone, temporary neurotrophic factors are secreted from the Müller cells, conferring neuroprotection in these cells.

BACKGROUND: Glaucoma is multifactorial, but the interrelationship between risk factors and structural changes remains unclear. Here, we adjusted for confounding factors in glaucoma patients with differing risk factors, and compared differences in structure and susceptible areas in the optic disc and macula. METHODS: In 458 eyes with glaucoma, we determined confounding factors for intraocular pressure (IOP), central corneal thickness (CCT), axial length (AL), LSFG-measured ocular blood flow (OBF), which was assessed with laser speckle flowgraphy-measured mean blur rate in the tissue area (MT) of the optic nerve head, biological antioxidant potential (BAP), and systemic abnormalities in diastolic blood pressure (dBP). To compensate for measurement bias, we also analyzed corrected IOP (cIOP; corrected for CCT) and corrected MT (cMT; corrected for age, weighted retinal ganglion cell count, and AL). Then, we determined the distribution of these parameters in low-, middle-, and high-value subgroups and compared them with the Kruskal-Wallis test. Pairwise comparisons used the Steel-Dwass test. RESULTS: The high-cIOP subgroup had significantly worse mean deviation (MD), temporal, superior, and inferior loss of circumpapillary retinal nerve fiber layer thickness (cpRNFLT), and large cupping. The low-CCT subgroup had temporal cpRNFLT loss; the high-CCT subgroup had low cup volume. The high-AL subgroup had macular ganglion cell complex thickness (GCCT) loss; the low-AL subgroup had temporal cpRNFLT loss. The high-systemic-dBP subgroup had worse MD, total, superior, and inferior cpRNFLT loss and macular GCCT loss. The low-BAP subgroup had more male patients, higher dBP, and cpRNFLT loss in the 10 o'clock area. The high-OBF subgroup had higher total, superior and temporal cpRNFLT and macular GCCT. CONCLUSIONS: Structural changes and local susceptibility to glaucomatous damage show unique variations in patients with different risk factors, which might suggest that specific risk factors induce specific types of pathogenesis and corresponding glaucoma phenotypes. Our study may open new avenues for the development of precision medicine for glaucoma.

Purpose: Retinal nerve fiber layer defects (RNFLDs) become enlarged with glaucoma progression. We measured the RNFLD angle and investigated whether it was correlated with deterioration of the visual field in patients with glaucoma. Methods: This study included 84 eyes of 84 patients with open-angle glaucoma (mean deviation [MD] = -6.51 ± 5.91 dB, follow-up period = 2.82 ± 0.74 years) with the RNFLDs, who underwent en face swept-source optical coherence tomography (SS-OCT) wide scans (12 × 9 mm) at least 6 times. The RNFLD angle was measured as the intersection between the RNFLD and a circle centered on the disc with a radius half the distance between the disc and the fovea. Slopes for the RNFLD angle, macular ganglion cell layer thickness (GCCT), and circumpapillary RNFL thickness (cpRNFLT) were compared with the MD slope, as measured with the Humphrey field analyzer 24-2 program. Results: The correlation coefficients with MD slope were -0.67 for the RNFLD angle slope (P < 0.001), 0.15 for the macular GCCT slope (P = 0.163), and 0.04 for the cpRNFLT slope (P = 0.719). The RNFLD angle tended to increase as the number of disc hemorrhage occurrences increased (rs = 0.31, P = 0.004). The RNFLD angle slope also had good predictive power for glaucoma progression (area under the receiver operating characteristic curve = 0.88, 95% confidence interval = 0.81-0.95). Conclusions: We found that the RNFLD angle slope was more closely associated with the MD slope than were other OCT parameters. This suggests that measurement of the RNFLD angle with en face OCT images could be effective in evaluating glaucoma progression. Translational Relevance: Our study provides a method for monitoring glaucoma progression with SS-OCT.

Detection, diagnosis, and treatment of ophthalmic diseases depend on extraction of information (features and/or their dimensions) from the images. Deep learning (DL) model are crucial for the automation of it. Here, we report on the development of a lightweight DL model, which can precisely segment/detect the required features automatically. The model utilizes dimensionality reduction of image to extract important features, and channel contraction to allow only the required high-level features necessary for reconstruction of segmented feature image. Performance of present model in detection of glaucoma from optical coherence tomography angiography (OCTA) images of retina is high (area under the receiver-operator characteristic curve AUC ~ 0.81). Bland-Altman analysis gave exceptionally low bias (~ 0.00185), and high Pearson's correlation coefficient (p = 0.9969) between the parameters determined from manual and DL based segmentation. On the same dataset, bias is an order of magnitude higher (~ 0.0694, p = 0.8534) for commercial software. Present model is 10 times lighter than Unet (popular for biomedical image segmentation) and have a better segmentation accuracy and model training reproducibility (based on the analysis of 3670 OCTA images). High dice similarity coefficient (D) for variety of ophthalmic images suggested it's wider scope in precise segmentation of images even from other fields. Our concept of channel narrowing is not only important for the segmentation problems, but it can also reduce number of parameters significantly in object classification models. Enhanced disease diagnostic accuracy can be achieved for the resource limited devices (such as mobile phone, Nvidia's Jetson, Raspberry pi) used in self-monitoring, and tele-screening (memory size of trained model ~ 35 MB).

Acute primary angle closure (APAC) is rare in young adults (those under approximately 40 years old) and pregnant women. Here, we report the case of a 37-year-old primigravid woman with APAC caused by plateau iris after the use of ritodrine (a β2 stimulator) that was successfully resolved by clear-lens extraction five months after delivery. The patient presented with pain in her right eye after ritodrine infusion for threatened premature labor at 23 weeks of gestation. Her visual acuity was 20/40, and her intraocular pressure (IOP) was 31 mmHg in her right eye. The patient was diagnosed as having APAC with plateau iris based on ultrasound biomicroscopy (UBM) findings of irido-angle touch, anterior dislocation of the ciliary process, and an absent ciliary sulcus. The effectiveness of treatment with pilocarpine eyedrops was limited, and argon laser peripheral iridoplasty did not succeed in reducing IOP. An immediate resolution was achieved with clear-lens extraction. IOP has since stayed within 14-16 mmHg without any medication for seven years. This is the first reported case of APAC complicated with plateau iris after ritodrine use in a pregnant woman. This condition is rare in young adults, making it difficult to diagnose; however, UBM can be of great help. In this case, clear-lens extraction led to a successful outcome. Our case suggests that attention should be paid to drug associations when APAC occurs with plateau iris.

Purpose: To investigate the effect of plant-derived antioxidant compounds, identified with primary culture screening, on retinal ganglion cell (RGC) survival in mice under excitotoxic conditions. Additionally, to determine the effect of these compounds on the involvement of calpain inactivation. Materials and Methods: Plant-derived antioxidant compounds including hesperidin, crocetin, and Tamarindus indica were administrated orally to C57BL/6J mice. The levels of lipid oxidation and calpain activation were assessed with a TBARS assay and western blotting. RGC survival was evaluated with a TUNEL assay and RBPMS immunostaining after intravitreal injection of NMDA. Results: Plant-derived antioxidant compounds significantly ameliorated the increase in the level of MDA in the retinas after NMDA injury. Cleaved α-fodrin fragments were detected in the NMDA-injured retinas, and these fragments were significantly lower in mice that received the plant-derived antioxidant compounds. The plant-derived antioxidants also ameliorated increases in TUNEL-positive cells and RGC death after NMDA injection. Conclusion: These results indicate that oral administration of plant-derived antioxidant compounds such as hesperidin, crocetin, and Tamarindus indica suppressed RGC death. This oral supplementation decreased lipid oxidation and excessive calpain activation in NMDA-injured retinas. Thus, our newly developed antioxidant supplement has a potential role in neuroprotective treatment for retinal diseases, such as glaucoma.

Glaucoma is a leading cause of blindness worldwide and is characterized by degeneration associated with the death of retinal ganglion cells (RGCs). It is believed that glaucoma is a group of heterogeneous diseases with multifactorial pathomechanisms. Here, we investigate whether anti-inflammation treatment with an ER stress blockade can selectively promote neuroprotection against NMDA injury in the RGCs. Retinal excitotoxicity was induced with an intravitreal NMDA injection. Microglial activation and neuroinflammation were evaluated with Iba1 immunostaining and cytokine gene expression. A stable HT22 cell line transfected with an NF-kB reporter was used to assess NF-kB activity after hesperidin treatment. CHOP-deficient mice were used as a model of ER stress blockade. Retinal cell death was evaluated with a TUNEL assay. As results, in the NMDA injury group, Iba1-positive microglia increased 6 h after NMDA injection. Also at 6 h, pro-inflammatory cytokines and chemokine increased, including TNFα, IL-1b, IL-6 and MCP-1. In addition, the MCP-1 promoter-driven EGFP signal, which we previously identified as a stress signal in injured RGCs, also increased; hesperidin treatment suppressed this inflammatory response and reduced stressed RGCs. In CHOP-deficient mice that received an NMDA injection, the gene expression of pro-inflammatory cytokines, chemokines, markers of active microglia, and inflammatory regulators was greater than in WT mice. In WT mice, hesperidin treatment partially prevented retinal cell death after NMDA injury; this neuroprotective effect was enhanced in CHOP-deficient mice. These findings demonstrate that ER stress blockade is not enough by itself to prevent RGC loss due to neuroinflammation in the retina, but it has a synergistic neuroprotective effect after NMDA injury when combined with an anti-inflammatory treatment based on hesperidin.

INTRODUCTION: Optic neuritis (ON) is a major phenotype of clinical attack related to demyelinating neurological diseases of the central nervous system, including multiple sclerosis (MS), anti-aquaporin-4 (AQP4) antibody-positive neuromyelitis optica spectrum disorder (NMOSD), and anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). As the concept of MOGAD is relatively new, the long-term visual outcomes after ON in MOGAD remains unclear. METHODS: To elucidate the long-term visual prognosis after ON in MOGAD, patients with MOGAD whose visual acuity were regularly followed for more than 5 years from the onset of ON were enrolled. Best-corrected visual acuity (BCVA) at nadir in the acute phase and at 1 and 5 years from onset was evaluated. The data from patients with MOGAD were compared with those from patients with MS or anti-AQP4-positive NMOSD. RESULTS: Twenty-three patients (31 ON-involved eyes) with MOGAD, 20 patients (24 ON-involved eyes) with MS, and 22 patients (24 ON-involved eyes) with anti-AQP4-positive NMOSD were evaluated. All BCVA at nadir, 1 year, and 5 years from the onset of ON were much worse in anti-AQP4-positive NMOSD than in MS (p = 0.0024) and MOGAD (p = 0.0014) patients. In MOGAD and anti-AQP4-positive NMOSD, the serum disease-specific antibody titer was not associated with the subsequent visual prognosis. Visual acuity had almost fully recovered spontaneously or shortly after initiating acute treatment in 22 of the 23 patients with MOGAD-ON. The administration of high-dose intravenous steroid therapy further facilitated early recovery of visual acuity. Meanwhile, a small fraction of patients with extensive optic nerve lesions involving the chiasma irreversibly experienced severe visual impairment despite appropriate acute treatment. CONCLUSION: Although a small fraction of patients with MOGAD who presented with extensive optic nerve lesions experienced irreversible severe visual impairment, the long-term visual outcomes after 5 years from ON in patients with MOGAD were generally as good as that in patients with MS and much better than that in patients with anti-AQP4-positive NMOSD.

Administration of the mitochondrial complex I inhibitor rotenone provides an excellent model to study the pathomechanism of oxidative stress-related neural degeneration diseases. In this study, we examined the glial roles in retinal cell survival and degeneration under the rotenone-induced oxidative stress condition. Mouse-derived Müller, microglial (BV-2), and dissociated retinal cells were used for in vitro experiments. Gene expression levels and cell viability were determined using quantitative reverse transcription-polymerase chain reaction and the alamarBlue assay, respectively. Conditioned media were prepared by stimulating glial cells with rotenone. Retinal ganglion cells (RGCs) and inner nuclear layer (INL) were visualized on rat retinal sections by immunohistochemistry and eosin/hematoxylin, respectively. Rotenone dose-dependently induced glial cell death. Treatment with rotenone or rotenone-stimulated glial cell-conditioned media altered gene expression of growth factors and inflammatory cytokines in glial cells. The viability of dissociated retinal cells significantly increased upon culturing in media conditioned with rotenone-stimulated or Müller cell-conditioned media-stimulated BV-2 cells. Furthermore, intravitreal neurotrophin-5 administration prevented the rotenone-induced reduction of RGC number and INL thickness in rats. Thus, glial cells exerted both positive and negative effects on retinal cell survival in rotenone-induced neural degeneration via altered expression of growth factors, especially upregulation of microglia-derived Ntf5, and proinflammatory cytokines.

OBJECTIVE: The aim of this study was to report the possible association between minor trauma to the eyes and the subsequent occurrence of optic neuritis in patients with serum anti-aquaporin-4 (AQP4) antibody-positive neuromyelitis optica spectrum disorder (NMOSD). METHODS: Herein, we present three patients who developed acute optic neuritis with visual disturbances after accidental minor trauma to their eyes, without any fundus abnormality or orbital floor fractures present. RESULTS: Two of the three patients had a preceding history of neurological disturbances compatible with NMOSD (e.g., myelitis, area postrema syndrome) before the occurrence of trauma. One patient was rapidly treated with steroid pulse therapy and plasmapheresis, and he fully recovered visual acuity. The other two, who were left untreated in the acute phase, had sequelae of severe visual disturbances in the affected eyes. CONCLUSIONS: These cases suggest possible association between minor trauma to the eyes and the subsequent occurrence of optic neuritis in patients with serum anti-AQP4 antibodies. Avoiding ocular trauma and early administration of steroid pulse therapy in response to optic neuritis after trauma are desired in such cases.

Purpose: Oxidative stress may be a risk factor for glaucoma, and many previous reports have suggested that antioxidants could be a promising treatment. Here, we investigated the effects of a novel supplement containing three food-derived antioxidants (hesperidin, crocetin, and Tamarindus indica) on markers of oxidative stress in patients with glaucoma. Patients and Methods: This study had a prospective, single arm design. Thirty Japanese glaucoma patients were recruited and given 4 tablets with ample water twice a day for 8 weeks. The treatment was stopped, and the subjects were followed for an additional 8 weeks. We measured biological antioxidant potential (BAP) with a free radical analyzer. We also measured urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG; a marker of oxidative DNA damage). Clinical laboratory data were measured in venous blood samples. Clinical parameters were also recorded. Comparisons used a one-way analysis of variance (ANOVA) followed by Dunnett's test. Results: The 8-OHdG level was not reduced. We also divided the patients into groups with high or low oxidative stress. In patients with relatively high oxidative stress, the 8-OHdG level was significantly reduced at weeks 4, 8, 12, and 16 (P < 0.001, P < 0.01, P < 0.01, P < 0.01), and BAP was significantly elevated at weeks 8 and 12 (P = 0.03, P = 0.04). In patients with relatively low oxidative stress, the 8-OHdG level was not significantly reduced during supplement intake but was significantly elevated at weeks 12 and 16 (P =0.03, P = 0.04), while BAP was not significantly elevated. Conclusion: An 8-week oral course of antioxidant supplementation was effective in patients with a high oxidative stress level. Dietary supplementation could hold promise in the treatment of systemic oxidative stress-related diseases.

Systemic antioxidative status has been implicated in glaucoma pathogenesis. Additionally, corneal hysteresis (CH) may contribute to glaucoma progression. Here, we evaluated the relationship between biological antioxidant potential (BAP) and CH. This study included 103 patients with open-angle glaucoma (OAG). We used a free radical analyzer to measure BAP, and an ocular response analyzer to measure CH and corneal resistance factor (CRF). We evaluated the relationship between systemic oxidative stress and other clinical parameters with Spearman's rank correlation test and a multi-regression analysis. BAP was not correlated to either CH or CRF in the male or female OAG patients. BAP was correlated to both CH and CRF in the female OAG patients older than 57 years (r = 0.51, P = 0.003; r = 0.49, P = 0.004), but uncorrelated in the female OAG patients younger than 57 years. Multiple regression analysis revealed that BAP independently contributed to CH (P = 0.025) and CRF (P = 0.015) in the older female OAG patients. Systemic oxidative stress may significantly affect the viscoelasticity of the cornea in older female OAG patients. Future studies are needed to confirm that low systemic antioxidative status and low corneal hysteresis contribute to glaucoma pathogenesis.

Objective: The purpose of this study was to elucidate the rapid impact of high-dose intravenous methylprednisolone pulse therapy (1,000 mg/day for 3 days) on the eventual visual prognosis in patients with serum anti-aquaporin-4 immunoglobulin G (AQP4-IgG)-positive neuromyelitis optica spectrum disorders (NMOSDs) who had an attack of optic neuritis (ON). Methods: Data from 32 consecutive NMOSD patients (1 male and 31 female) with at least one ON attack, involving a total of 36 ON-involved eyes, were evaluated. The following variables at ON onset were evaluated: sex, age at the first ON episode, visual acuity at nadir, visual acuity after 1 year, duration from ON onset to treatment for an acute ON attack, cycles of high-dose intravenous methylprednisolone pulse therapy for the ON attack, and cycles of plasmapheresis for the ON attack. Among the 36 ON-involved eyes, 27 eyes were studied using orbital MRI with a short-T1 inversion recovery sequence and gadolinium-enhanced fat-suppressed T1 imaging before starting treatment in the acute phase. Results: In univariate analyses, a shorter duration from ON onset to the initiation of high-dose intravenous methylprednisolone pulse therapy favorably affected the eventual visual prognosis 1 year later (Spearman's rho = 0.50, p = 0.0018). The lesion length on orbital MRI was also correlated with the eventual visual prognosis (rho = 0.68, p < 0.0001). Meanwhile, the days to steroid pulse therapy and lesion length on orbital MRI did not show a significant correlation. These findings suggest that the rapidness of steroid pulse therapy administration affects the eventual visual prognosis independent of the severity of ON. In multivariate analysis, a shorter time from ON onset to the start of acute treatment (p = 0.0004) and a younger age at onset (p = 0.0071) were significantly associated with better visual outcomes. Conclusions: Rapid initiation of high-dose intravenous methylprednisolone pulse therapy is essential to preserve the eventual visual acuity in patients with serum AQP4-IgG-positive NMOSD. Once clinicians suspect acute ON with serum AQP4-IgG, swift administration of steroid pulse therapy before confirming the positivity of serum AQP4-IgG would be beneficial for preserving visual function.

PURPOSE: To investigate the effect of mitochondrial dysfunction on the autoregulation of blood flow, by measuring levels of glutathione, an indicator of mitochondrial dysfunction, in glaucoma patients. METHODS: Fifty-six OAG patients and 21 age-matched controls underwent a blood assay. Mitochondrial function was measured according to the levels of total glutathione (t-GSH), reduced GSH (GSH), and oxidized GSH (GSSG, glutathione disulfide) in peripheral blood mononuclear cells. Ocular blood flow in the optic nerve head was assessed with laser speckle flowgraphy parameters, including acceleration time index (ATI). We determined correlations between these measurements and other clinical parameters. Furthermore, we investigated the association between glutathione levels and glaucoma with a logistic regression analysis. Finally, we calculated the area under the receiver operating characteristic (ROC) curve in order to determine the power of redox index (the log GSH/GSSG ratio) to distinguish the groups. RESULTS: OAG patients demonstrated significantly higher GSSG levels and a lower redox index than the controls (p = 0.01, p = 0.01, respectively), but total GSH and reduced GSH levels were similar in the OAG subjects and controls (p = 0.80, p = 0.94, respectively). Additionally, redox index was significantly correlated with mean deviation (MD) of the visual field (r = 0.29, p = 0.03) and ATI (r = -0.30, p = 0.03). Multiple linear regression analysis showed that redox index contributed to MD (p = 0.02) and ATI (p = 0.04). The receiver operating characteristic curve (AUC) analysis suggested that redox index could differentiate between control eyes and eyes with glaucoma (AUC; 0.70: 95% interval; 0.57-0.84). The cutoff point for redox index to maximize its sensitivity and specificity was 2.0 (sensitivity: 91.1%, specificity: 42.9%). CONCLUSIONS: These results suggest that redox index is lower in OAG patients than in controls. Thus, it is possible that mitochondrial dysfunction contributes to glaucoma pathogenesis by causing vascular alterations.

PURPOSE: To determine the potential of anterior-segment optical coherence tomography (AS-OCT) to predict posttrabeculectomy outcomes in neovascular glaucoma (NVG). PATIENTS AND METHODS: We recruited 45 eyes of 40 NVG patients who underwent trabeculectomy. The patients were divided into success and failure groups based on the posttrabeculectomy outcome after 12 months. AS-OCT findings were compared in the success and failure groups at 1 and 2 weeks and 1, 3, 6, and 12 months. We also analyzed early posttrabeculectomy bleb parameters with multiple logistic regression, stepwise multiple regression, and the receiver operating characteristic curve to evaluate the power of these parameters to predict long-term outcomes. RESULTS: Intraocular pressure at 6 and 12 months was lower in the success group than the failure group (P<0.0016=0.0048). Reflectivity of the bleb wall was higher in the failure group than the success group throughout the study (all: P<0.0016). Age and reflectivity of the bleb wall at 1 week were risk factors for failure with odds ratios for failure of 0.91 and 1.67. The area under the receiver operating characteristic curve for reflectivity of the bleb wall at 1 week was 0.943 with the cutoff set at 128.9 (sensitivity: 85.7%; specificity: 100.0%). Stepwise multiple regression analysis showed that reflectivity of the bleb wall at 1 week independently indicated the bleb survival period (β=-0.84; P<0.001). CONCLUSIONS: AS-OCT-measured reflectivity of the bleb wall, measured at 1 week of trabeculectomy for NVG, might be able to predict of the final status of the bleb.

Chloride imbalance between the serum and the cerebrospinal fluid (CSF) has been recently shown to exist in the acute phase of neuromyelitis optica (NMO). In this report, we studied the relation between the quotient of chloride (QCl) and the severity of optic neuritis (ON) in NMO patients. There was a positive correlation (R = 0.67; p < 0.05) between QCl and the length of ON-lesion. The visual prognosis also showed a positive correlation with QCl in the acute phase (R = 0.58; p < 0.05). These results support the theory that chloride imbalance between serum and CSF may trigger the ON in NMO spectrum disorders.

PURPOSE: Sleep apnoea syndrome (SAS) is often associated with glaucoma, and intermittent hypoxia, present in SAS, can contribute to glaucoma pathogenesis. However, the relationships between SAS, high systemic oxidative stress and the speed of glaucoma progression are unclear. Thus, we investigated these relationships in glaucoma patients with and without SAS. METHODS: Peripheral blood samples were collected from 166 eyes of 166 Japanese patients: 42 controls, 109 open-angle glaucoma (OAG) patients without SAS and 15 OAG patients with SAS. Prognostic factors for visual field defect progression were determined with logistic regression. Diacron reactive oxygen metabolites (dROM) and biological antioxidant potential (BAP) were measured with a free radical analyser. Clinical parameters were also recorded. Intergroup comparisons used the Mann-Whitney U test. RESULTS: Multiple regression analysis showed that SAS was a statistically significant contributing factor to fast visual field defect progression, defined as mean deviation (MD) slope ≤-2.0 dB/Y (SAS: odds ratio (OR) = 14.48; p = 0.002). The non-SAS and SAS groups had similar age, sex, intraocular pressure (IOP), axial length and antiglaucoma drug use. The SAS group had a significantly higher dROM level (p = 0.001), BAP level (p = 0.038) and steeper MD slope (p = 0.001) than the non-SAS group. CONCLUSION: Glaucoma patients with SAS have higher dROM, as well as steeper MD slope, than patients without SAS, suggesting that SAS may induce systemic oxidative stress and promote glaucomatous visual field defect progression.

PURPOSE: To analyze cytokine profiles of the aqueous humor of eyes with primary open-angle glaucoma (POAG), neovascular glaucoma (NVG), and cataract (as controls). METHODS: A multiplex bead assay was used to measure concentrations of 27 cytokines in aqueous humor samples from 54 eyes. RESULTS: Detection rates were as follows: IL-7: NVG higher than POAG; IL-10: POAG lower than cataract or NVG; and GM-CSF: cataract higher than POAG or NVG. Concentrations were as follows: IL-8, IP-10, MCP-1, and MIP-1β: POAG and NVG higher than cataract; IL-9: POAG lower than NVG; IL-12: POAG lower than cataract or NVG; and VEGF: NVG higher than cataract or POAG and POAG lower than cataract. Further analysis showed that IL-8, IP-10, MCP-1, and MIP-1β were correlated with intraocular pressure and age. CONCLUSIONS: The detection rates and levels of various cytokines had different patterns in POAG and NVG patients, suggesting distinctive alterations in the microenvironment in different types of glaucoma.

BACKGROUND: The aims of this study were to investigate glaucomatous morphological changes quantitatively in the visual cortex of the brain with voxel-based morphometry (VBM), a normalizing MRI technique, and to clarify the relationship between glaucomatous damage and regional changes in the visual cortex of patients with open-angle glaucoma (OAG). METHODS: Thirty-one patients with OAG (age: 55.9 ± 10.7, male: female = 9: 22) and 20 age-matched controls (age: 54.9 ± 9.8, male: female = 10: 10) were included in this study. The cross-sectional area (CSA) of the optic nerve was manually measured with T2-weighed MRI. Images of the visual cortex were acquired with T1-weighed 3D magnetization-prepared rapid acquisition with gradient echo (MPRAGE) sequencing, and the normalized regional visual cortex volume, i.e., gray matter density (GMD), in Brodmann areas (BA) 17, 18, and 19, was calculated with a normalizing technique based on statistic parametric mapping 8 (SPM8) analysis. We compared the regional GMD of the visual cortex in the control subjects and OAG patients. Spearman's rank correlation analysis was used to determine the relationship between optic nerve CSA and GMD in BA 17, 18, and 19. RESULTS: We found that the normal and OAG patients differed significantly in optic nerve CSA (p < 0.001) and visual cortex GMD in BA 17 (p = 0.030), BA 18 (p = 0.003), and BA 19 (p = 0.005). In addition, we found a significant correlation between optic nerve CSA and visual cortex GMD in BA 19 (r = 0.33, p = 0.023), but not in BA 17 (r = 0.17, p = 0.237) or BA 18 (r = 0.24, p = 0.099). CONCLUSION: Quantitative MRI parametric evaluation of GMD can detect glaucoma-associated anatomical atrophy of the visual cortex in BA 17, 18, and 19. Furthermore, GMD in BA 19 was significantly correlated to the damage level of the optic nerve, as well as the retina, in patients with OAG. This is the first demonstration of an association between the cortex of the brain responsible for higher-order visual function and glaucoma severity. Evaluation of the visual cortex with MRI is thus a very promising potential method for objective examination in OAG.

We compared the retinal thickness in the unaffected eyes among the following subtypes of unilateral optic neuritis (ON): multiple sclerosis (MS-ON), neuromyelitis optica spectrum disorder with anti-AQP4 autoantibody (AQP4-ON), patients with serum anti-MOG antibody (MOG-ON), and idiopathic ON. In the chronic phase, macular GCC and circum-papillary RNFL in the unaffected eyes were both atrophied in MS-ON and AQP4-ON, but were not atrophied in the others. Titers of anti-AQP4-Ab was suggested to be associated with such latent neurodegenerative process in AQP4-ON. Long-term follow up of OCT is recommended even in the unaffected side in MS-ON and AQP4-ON.

Systemic oxidative stress is thought to be an important factor in the pathogenesis of glaucoma. In particular, low systemic antioxidative capacity, which normally counters oxidative stress, may contribute to glaucoma. Thus, we investigated the association between biological antioxidant potential (BAP), a biomarker of systemic antioxidative capacity, and glaucoma severity in patients with open-angle glaucoma (OAG). This study included 480 eyes of 240 patients with OAG and 66 healthy control eyes. We measured the BAP serum level with a free radical analyzer and compared it with a weighted estimate of the number of retinal ganglion cells (wrgc), derived from circumpapillary retinal nerve fiber layer thickness and visual field mean deviation. We found that wrgc was uncorrelated with BAP in the overall, male, and female OAG patients, but was correlated in young (aged ≤ 65 years) male OAG patients (better eye: r = 0.33, P = 0.02; worse eye: r = 0.27, P = 0.047). Furthermore, a mixed-effects regression analysis revealed that BAP was an independent contributing factor to wrgc in young male OAG patients (P = 0.02). Thus, systemic antioxidant capacity was associated with glaucomatous damage in relatively young male patients, suggesting that anti-oxidant therapy might be more effective in these patients.

BACKGROUND: It has been suggested that local and systemic oxidative stress levels are causal risk factors for glaucoma. AIM: To evaluate the effect of age on the role of systemic oxidative stress in open-angle glaucoma (OAG). METHODS: This study included 502 eyes of 251 Japanese patients with OAG. Systemic oxidative stress was assessed with skin autofluorescence (SAF), an indicator of advanced glycogen end products. We selected the youngest and oldest patients by quartile (≤58 and ≥74 years old, respectively) and determined the univariate correlation between SAF and mean deviation (MD) of the visual field in both eyes of each group. We also investigated the association between SAF and glaucoma in the youngest group with a logistic regression analysis. RESULTS: The younger subjects with OAG with high SAF had significantly lower better-eye MD than the younger subjects with normal SAF (p<0.01), but the older subjects had similar better-eye MD regardless of SAF level. Furthermore, SAF was negatively correlated with MD in the youngest subjects (better eye: r=-0.35, p<0.01, worse eye: r=-0.28, p=0.02), but not in the older subjects. Finally, mixed-effects regression analysis showed that SAF contributed to the MD in the younger patients with OAG (p=0.01). CONCLUSIONS: We found that the relationship between systemic oxidative stress and visual field loss was strongest in relatively young patients with OAG, suggesting that the potential benefit of antioxidant therapies to combat systemic oxidative stress might be dependent on the age of the patient.

PURPOSE: To investigate the effect of bilberry extract anthocyanins on retinal ganglion cell (RGC) survival after optic nerve crush. Additionally, to determine details of the mechanism of the neuroprotective effect of bilberry extract anthocyanins and the involvement of endoplasmic reticulum stress suppression in the mouse retina. MATERIALS AND METHODS: Anthocyanins in bilberry extract (100 mg/kg/day or 500 mg/kg/day) were administrated orally to C57BL/6J mice. The expression levels of various molecular chaperones were assessed with quantitative reverse-transcription polymerase chain reaction, Western blotting, and immunohistochemistry. RGC survival was evaluated by measuring the gene expression of RGC markers and counting retrogradely labeled RGCs after optic nerve crush. RESULTS: The protein levels of Grp78 and Grp94 increased significantly in mice after bilberry extract administration. Increased Grp78 and Grp94 levels were detected in the inner nuclear layer and ganglion cell layer of the retina, surrounding the RGCs. Gene expression of Chop, Bax, and Atf4 increased in mice after optic nerve crush and decreased significantly after oral bilberry extract administration. RGC survival after nerve crush also increased with bilberry extract administration. CONCLUSION: These results indicate that oral bilberry extract administration suppresses RGC death. Bilberry extract administration increased Grp78 and Grp94 protein levels, an effect which may underlie the neuroprotective effect of bilberry extract after optic nerve crush. Thus, bilberry extract has a potential role in neuroprotective treatments for retinal injuries, such as those which occur in glaucoma.

PURPOSE: To evaluate the optic nerve head (ONH) microcirculation in autosomal dominant optic atrophy (ADOA) patients. METHODS: This study comprised 22 eyes of 12 ADOA patients, diagnosed according to clinical findings including family history and the presence of mutations in the OPA1 gene. Twenty-four normal eyes of 24 age-matched subjects, with either the right or left eye randomly selected for use, served as controls. Circumpapillary retinal nerve fibre layer thickness (cpRNFLT) and mean blur rate (MBR) in the ONH were determined with optical coherence tomography (OCT) and laser speckle flowgraphy (LSFG), respectively. For each ONH quadrant (superior, temporal, inferior and nasal), the MBR and cpRNFLT ratio was also calculated by dividing tissue MBR in that quadrant by tissue MBR in the entire ONH and by dividing cpRNFLT in that quadrant by cpRNFLT in the entire ONH respectively. RESULTS: Mean blur rate (MBR) in all quadrants was significantly lower in the ADOA patients than in the controls (p < 0.001 in each). The MBR ratio was significantly lower in the ADOA patients only in the temporal quadrant (p < 0.001). Similarly, cpRNFLT was lower in the ADOA patients in all quadrants (p < 0.001 in each), and the cpRNFLT ratio was lower in the temporal quadrant (p < 0.001). CONCLUSION: Reduced blood flow in the temporal optic disc in ADOA patients is associated with reduced temporal cpRNFLT, suggesting that both are caused by damage to the papillomacular bundle. The anatomical characteristics of the papillomacular bundle may make it especially susceptible to mitochondrial dysfunction-induced damage, which occurs in ADOA.

[This corrects the article on p. 3551 in vol. 7, PMID: 27699120.].

Estimation of polarimetric parameters has been a fundamental issue to assess biological tissues that have form birefringence or polarization scrambling in polarization-sensitive optical coherence tomography (PS-OCT). We present a mathematical framework to provide a maximum likelihood estimation of the target covariance matrix and its incoherent target decomposition to estimate a Jones matrix of a dominant scattering mechanism, called Cloude-Pottier decomposition, thereby deriving the phase retardation and the optic axis of the sample. In addition, we introduce entropy that shows the randomness of the polarization property. Underestimation of the entropy at a low sampling number is mitigated by asymptotic quasi maximum likelihood estimator. A bias of the entropy from random noises is corrected to show only the polarization property inherent in the sample. The theory is validated with experimental measurements of a glass plate and waveplates, and applied to the imaging of a healthy human eye anterior segment as an image filter.

BACKGROUND: The aim of the study is to determine the relationship between post-trabeculectomy bleb structure evaluated using anterior segment optical coherence tomography (AS-OCT) and postoperative intraocular pressure (IOP). DESIGN: Rretrospective is showed for the design of this study. PARTICIPANTS: There are twenty-seven eyes of 27 trabeculectomy patients. METHODS: We drew contour lines for the bleb and cleft on 8-radius-scanned AS-OCT images, and determined correlations of AS-OCT measurements to postoperative IOP at 6 months. MAIN OUTCOME MEASURES: The parameter used in this study is an anterior segment optical coherence tomography measurements of bleb structure, including cleft volume, wall volume, and the brightness of the bleb wall. RESULTS: We found significant correlations between postoperative IOP at 6 months and cleft volume at 3 and 6 months (r = -0.56, P = 0.007 and r = -0.82, P <0.001), bleb wall volume at 6 months (r = -0.48, P = 0.042), bleb vertical brightness at 3 and 6 months (r = 0.73, P < 0.001 and r = 0.49, P = 0.040), and bleb horizontal brightness at 1 week, 2 weeks, 3 months and 6 months (r = 0.49, P = 0.016, r = 0.65, P < 0.001, r = 0.52, P = 0.013 and r = 0.71, P = 0.001). A stepwise multiple regression analysis of bleb structural measurements made ≤2 weeks postoperatively showed that the strongest independent factor indicating postoperative IOP at 6 months was bleb horizontal brightness at 2 weeks (β = 0.50, P = 0.006). CONCLUSIONS: Early postoperative AS-OCT measurements of blebs, especially horizontal brightness of the bleb wall, were associated with postoperative IOP at 6 months. AS-OCT measurements of blebs may be useful predictors of trabeculectomy outcomes.

PURPOSE: To evaluate the association between ocular blood flow and biomarkers of systemic oxidative stress, as well as the potential of these biomarkers to assess normal-tension glaucoma (NTG). METHODS: This study included 73 eyes of 73 patients with NTG. We assessed ocular blood flow by measuring mean blur rate (MBR) in the optic nerve head using laser speckle flowgraphy, both overall and separately in the vessel and tissue areas. We also measured urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and skin autofluorescence (SAF), and lastly, determined correlations between these measurements and with other clinical parameters. RESULTS: SAF was correlated with age, circumpapillary retinal nerve fiber layer thickness (cpRNFLT), mean deviation (MD), and overall MBR (P = 0.003, P = 0.013, P = 0.015 and P = 0.006, respectively). SAF and 8-OHdG were both correlated with tissue-area MBR (P = 0.006 and P = 0.010, respectively). Visual acuity, cpRNFLT, mean deviation and tissue-area MBR had a significant tendency to change with NTG severity (P = 0.014, P < 0.001, P < 0.001 and P = 0.006, respectively). Multiple regression analysis revealed that cpRNFLT and 8-OHdG were independent contributing factors to MD (P < 0.001 and P = 0.040, respectively), and that cpRNFLT and 8-OHdG were independent contributing factors to tissue-area MBR (P = 0.005 and P = 0.028, respectively). CONCLUSIONS: We found a close relationship between cpRNFLT, MD, tissue MBR, SAF and 8-OHdG, suggesting that systemic oxidative stress is associated with decreased ocular blood flow and may be involved in the pathogenesis of NTG.

We demonstrate a prototype system of polarization-sensitive optical coherence tomography (PS-OCT) designed for clinical studies of the anterior eye segment imaging. The system can measure Jones matrices of the sample with depth-multiplexing of two orthogonal incident polarizations and polarization-sensitive detection. An optical clock is generated using a quadrature modulator and a logical circuit to double the clock frequency. Systematic artifacts in measured Jones matrices are theoretically analyzed and numerically compensated using signals at the surface of the sample. Local retardation images of filtering blebs after trabeculectomy show improved visualization of subconjunctival tissue, sclera, and scar tissue of the bleb wall in the anterior eye segment.

PURPOSE: To evaluate laser speckle flowgraphy (LSFG) measurements of the optic nerve head (ONH) blood flow (BF) response to hyperoxia. METHODS: This prospective study included 30 eyes of 30 healthy volunteers (mean age: 28.5 ± 4.0, male:female = 13:17). The testing protocol had three phases: in the baseline phase, subjects breathed room air; in the hyperoxic phase, they breathed pure oxygen (6 L/min) for 15 min; and in the recovery phase, they were room air for 15 min. LSFG measurements of mean blur rate (MBR), which represents ONH BF, were taken every minute. The MBR ratio in the hyperoxic and recovery phases was calculated with reference to this baseline. Clinical parameters, including systemic blood pressure, pulse rate, and saturation of pulse-oximetry oxygen (SpO2), were measured every 5 min. RESULTS: SpO2 increased significantly during hyperoxia (97.3 ± 1.1% to 99.3 ± 0.7%, p < 0.001). While clinical parameters were similar in hyperoxia and baseline, MBR decreased significantly after 2 min of hyperoxia (90.8 ± 12.6%, p = 0.02), stayed steady throughout hyperoxia (mean: 89.5 ± 10.8%, p range: <0.001-0.04) compared with baseline, and returned to baseline 1 min after recovery (93.7 ± 10.3%, p = 0.25). A linear regression using a third-order polynomial fitting curve analysis revealed that the time to reach minimum MBR was 7.78 min (adjusted R(2 )= 0.87). CONCLUSION: LSFG could effectively assess ONH BF changes during hyperoxia.

Artemin, a recently discovered member of the glial cell line-derived neurotrophic factor (GDNF) family, has neurotrophic effects on damaged neurons, including sympathetic neurons, dopamine neurons, and spiral ganglion neurons both in vivo and in vitro. However, its effects on retinal cells and its intracellular signaling remain relatively unexplored. During development, expression of GFRα3, a specific receptor for artemin, is strong in the immature retina and gradually decreases during maturation, suggesting a possible role in the formation of retinal connections. Optic nerve damage in mature rats causes levels of GFRα3 mRNA to increase tenfold in the retina within 3 days. GFRα3 mRNA levels continue to rise within the first week and then decline. Artemin, a specific ligand for GFRα3, has a neuroprotective effect on axotomized retinal ganglion cells (RGCs) in vivo and in vitro via activation of the extracellular signal-related kinase- and phosphoinositide 3-kinase-Akt signaling pathways. Artemin also has a substantial effect on axon regeneration in RGCs both in vivo and in vitro, whereas other GDNF family members do not. Therefore, artemin/GFRα3, but not other GDNF family members, may be of value for optic nerve regeneration in mature mammals.

PURPOSE: To investigate the effect of K-115, a novel Rho kinase (ROCK) inhibitor, on retinal ganglion cell (RGC) survival in an optic nerve crush (NC) model. Additionally, to determine the details of the mechanism of K-115's neuroprotective effect in vivo and in vitro. METHODS: ROCK inhibitors, including K-115 and fasudil (1 mg/kg/d), or vehicle were administered orally to C57BL/6 mice. Retinal ganglion cell death was then induced with NC. Retinal ganglion cell survival was evaluated by counting surviving retrogradely labeled cells and measuring RGC marker expression with quantitative real-time polymerase chain reaction (qRT-PCR). Total oxidized lipid levels were assessed with a thiobarbituric acid-reactive substances (TBARS) assay. Reactive oxygen species (ROS) levels were assessed by co-labeling with CellROX and Fluorogold. Expression of the NADPH oxidase (Nox) family of genes was evaluated with qRT-PCR. RESULTS: The survival of RGCs after NC was increased 34 ± 3% with K-115, a significantly protective effect. Moreover, a similar effect was revealed by the qRT-PCR analysis of Thy-1.2 and Brn3a, RGC markers. Levels of oxidized lipids and ROS also increased with time after NC. NC-induced oxidative stress, including oxidation of lipids and production of ROS, was significantly attenuated by K-115. Furthermore, expression of the Nox gene family, especially Nox1, which is involved in the NC-induced ROS production pathway, was dramatically reduced by K-115. CONCLUSIONS: The results indicated that oral K-115 administration delayed RGC death. Although K-115 may be mediated through Nox1 downregulation, we found that it did not suppress ROS production directly. Our findings show that K-115 has a potential use in neuroprotective treatment for glaucoma and other neurodegenerative diseases.

PURPOSE: In this study, we set out to establish an in vivo animal model of oxidative stress in the retinal ganglion cells (RGCs) and determine whether there is a link between oxidative stress in the RGCs and the activation of calpain, a major part of the apoptotic pathway. MATERIALS AND METHODS: Oxidative stress was induced in the RGCs of C57BL/6 mice by the intravitreal administration of 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH, 30mM, 2μl). Control eyes were injected with 2μl of vehicle. Surviving Fluorogold (FG)-labeled RGCs were then counted in retinal flat mounts. Double staining with CellROX and Annexin V was performed to investigate the co-localization of free radical generation and apoptosis. An immunoblot assay was used both to indirectly evaluate calpain activation in the AAPH-treated eyes by confirming α-fodrin cleavage, and also to evaluate the effect of SNJ-1945 (a specific calpain inhibitor: 4% w/v, 100mg/kg, intraperitoneal administration) in these eyes. RESULTS: Intravitreal administration of AAPH led to a significant decrease in FG-labeled RGCs 7days after treatment (control: 3806.7±575.2RGCs/mm(2), AAPH: 3156.1±371.2RGCs/mm(2), P<0.01). CellROX and Annexin V signals were co-localized in the FG-labeled RGCs 24h after AAPH injection. An immunoblot assay revealed a cleaved α-fodrin band that increased significantly 24h after AAPH administration. Intraperitoneally administered SNJ-1945 prevented the cleavage of α-fodrin and had a neuroprotective effect against AAPH-induced RGC death (AAPH: 3354.0±226.9RGCs/mm(2), AAPH+SNJ-1945: 3717.1±614.6RGCs/mm(2), P<0.01). CONCLUSION: AAPH administration was an effective model of oxidative stress in the RGCs, showing that oxidative stress directly activated the calpain pathway and induced RGC death. Furthermore, inhibition of the calpain pathway protected the RGCs after AAPH administration.

Although axonal damage induces significant retinal ganglion cell (RGC) death, small numbers of RGCs are able to survive up to 7 days after optic nerve crush (NC) injury. To develop new treatments, we set out to identify patterns of change in the gene expression of axonal damage-resistant RGCs. To compensate for the low density of RGCs in the retina, we performed retrograde labeling of these cells with 4Di-10ASP in adult mice and 7 days after NC purified the RGCs with fluorescence-activated cell sorting. Gene expression in the cells was determined with a microarray, and the expression of Ho-1 was determined with quantitative PCR (qPCR). Changes in protein expression were assessed with immunohistochemistry and immunoblotting. Additionally, the density of Fluoro-gold-labeled RGCs was counted in retinas from mice pretreated with CoPP, a potent HO-1 inducer. The microarray and qPCR analyses showed increased expression of Ho-1 in the post-NC RGCs. Immunohistochemistry also showed that HO-1-positive cells were present in the ganglion cell layer (GCL), and cell counting showed that the proportion of HO-1-positive cells in the GCL rose significantly after NC. Seven days after NC, the number of RGCs in the CoPP-treated mice was significantly higher than in the control mice. Combined pretreatment with SnPP, an HO-1 inhibitor, suppressed the neuroprotective effect of CoPP. These results reflect changes in HO-1 activity to RGCs that are a key part of RGC survival. Upregulation of HO-1 signaling may therefore be a novel therapeutic strategy for glaucoma.

The aim of this study was to examine the effects of oral administration of kampo medical formulas on ocular blood flow (OBF). A crossover protocol was used to randomly administer five grams of yokukansan, tokishakuyakusan (TSS), keishibukuryogan, or hachimijiogan to 13 healthy blinded subjects (mean age: 37.3 ± 12.3 years). The mean blur rate, a quantitative OBF index obtained with laser speckle flowgraphy, was measured at the optic nerve head before and 30 minutes after administration. Blood pressure (BP) and intraocular pressure (IOP) were also recorded. No significant changes were observed in mean BP or IOP after the administration of any of the kampo medical formulas. There was a significant increase in OBF 30 minutes after administration of TSS (100% to 103.6 ± 6.9%, P < 0.01). Next, TSS was administered to 19 healthy subjects (mean age: 32.0 ± 11.0 years) and OBF was measured before and 15, 30, 45, and 60 minutes after administration. Plain water was used as a control. OBF increased significantly after TSS administration compared to control (P < 0.01) and also increased from 30 to 60 minutes after administration compared to baseline (P < 0.05). These results suggest that TSS can increase OBF without affecting BP or IOP in healthy subjects.

NF-E2 related factor 2 (Nrf2) is a key transcription factor that plays a pivotal role in endogenous protection against oxidative stress. However, the role of Nrf2 in visual disorders remains unclear. It has been reported that oxidative stress is thought of as one of the causes of glaucoma. Here, we investigate whether the function of Nrf2 in oxidative stress-induced retinal ganglion cell (RGC) death. This study used adult male Nrf2 deficient mice (Nrf2 KO) and age- and sex-matched wild-type (WT) mice. We dissociated and purified N-4-[4-didecylaminostryryl]-N-methyl-pyridinium iodide-labeled RGCs with fluorescence-activated cell sorting, and tried to detect the Nrf2 and Keap1 genes. In the absence of nerve crush (NC), the number of RGCs in Nrf2 KO mice was almost same as that in WT mice. 1-(2-cyano-3-, 12-dioxooleana-1, 9 (11)-dien-28-oyl) imidazole (CDDO-Im), an Nrf2 activator, prevented NC-induced loss of RGCs in WT mice. Seven days after NC, without treatment, the number of RGCs in Nrf2 KO mice was significantly lower than in WT mice. In addition, after CDDO-Im treatment, quantitative RT-PCR showed increased expression of antioxidant and phase II detoxifying enzymes. These results suggest that up-regulation of Nrf2 signaling after CDDO-Im treatment may be a novel therapeutic strategy for the protection of RGCs, especially in glaucoma. This study suggests that NF-E2 related factor 2 (Nrf2), a transcription factor, plays a pivotal role in counteracting oxidative stress. Most importantly, a neuroprotective effect against oxidative stress-induced retinal ganglion cell (RGC) death was achieved with the pharmacological Nrf2 activator CDDO-Im. This suggests that pharmacological treatment to up-regulate Nrf2 signaling may be a new therapeutic technique to protect RGCs.

The corneal epithelium exists at the surface of cornea and is easily damaged by external stresses such as UV radiation or physical injury. The Nrf2-mediated defense system plays a central role in protecting cells by activating genes against these types of stress. In this study, we investigated the role of the Nrf2-mediated defense system in corneal epithelial wound healing by using Nrf2-knockout (KO) mice. Nrf2 was expressed in the corneal epithelium of wild-type (WT) mice, but not in KO mice. Observation of wounds after 24h of healing revealed that healing of the corneal epithelium was significantly delayed in the Nrf2 KO mice, whereas Nrf2 was activated in the corneal epithelium of WT mice. Ki-67 staining revealed that the number of Ki-67-positive proliferating cells was significantly lower in the Nrf2 KO mice than in the WT mice at 24-36h after injury; however, these numbers were approximately equivalent by 48h. To clarify the role of Nrf2 during wound healing, we performed in vitro experiments with siRNA for Nrf2 and its suppressor Keap1. Nrf2 knockdown significantly delayed corneal epithelial cell migration, but did not affect cell proliferation. Conversely, Keap1 knockdown significantly accelerated cell migration. These results suggest that Nrf2 contributed to the corneal epithelial wound-healing process by accelerating cell migration, and Nrf2 would therefore be a good target for the treatment of corneal epithelial diseases such as dry eye or chronic corneal epithelial defect.

To describe how a high fat diet (HFD) and hyperglycemia initiate a sequence of calpain activation and oxidative stress associated with neuro-degenerative changes in diabetic retinopathy (DR), hyperglycemia was induced with streptozotocin in mice lacking the gene for calpastatin (CAST KO), and in mice lacking the gene for the transcription factor NF-E2 related factor 2 (Nrf2 KO). All animals were fed a HFD. Retinal ganglion cell (RGC) density was estimated by labeling with fluorogold and immunohistochemistry. A potent calpain inhibitor, SNJ-1945, was administered daily until the animals were sacrificed. In vitro, oxidative stress-induced RGC loss was evaluated in a high glucose culture medium with and without SNJ-1945. Retinal mRNA of calpain-1 and calpain-2 was measured by quantitative RT-PCR. Pre-apoptotic substrates of cleaved α-fodrin and synaptophysin protein were quantified by immunoblot analysis. Axonal damage was examined in transverse sections of the optic nerve. A HFD and hyperglycemia significantly increased RGC and axonal degeneration 3 weeks into the experiment. Levels of cleaved α-fodrin were increased. In the CAST KO mice, the neurotoxicity was augmented significantly. Gene manipulation of CAST and orally administered SNJ-1945 successfully modified calpain levels in the retina and prevented RGC death. In vitro, a high-glucose culture of retinal cells without antioxidants showed more RGC death than that with antioxidant treatment. The expression of synaptophysin was significantly suppressed by SNJ-1945 treatment. These results suggest that calpain plays a crucial role in metabolic-induced RGC degeneration caused by hyperglycemia and oxidative stress. Antioxidant and calpain inhibition offers important opportunities for future neuroprotective treatment against RGC death in various metabolic stress-induced diseases including DR.

PURPOSE: To investigate the relationship between the optic disc appearance and the progression of visual field defects in eyes with normal tension glaucoma (NTG). METHODS: Two hundred nine patients with NTG, who were being treated with topical antiglaucoma drugs and had been followed for at least 3 years, were studied. The baseline optic disc appearance was classified into 4 types: focal ischemic (FI), myopic glaucomatous (MY), senile sclerotic (SS), and generalized cup enlargement (GE). The progression of the NTG was assessed by the slope of the mean deviations (MDs) obtained from the visual field results collected during the follow-up examinations. The baseline and mean intraocular pressures (IOPs) were also followed. RESULTS: Twenty-seven patients were placed in the FI group, 63 into the MY group, 24 into the SS group, and 43 into the GE group. Fifty-two patients (24.9%) could not be classified. There were no significant differences in the percentage reduction of the IOP among the 4 groups. The MD slope in the GE group (-0.51±0.74 dB/y) was significantly steeper than that in the other groups. Regression analyses showed that the factors most associated with the MD slope were the age in the FI (r, -0.495) and the GE (r=0.496) groups, and the relative reduction of the IOP (r=0.413) in the SS group. None of the factors in the MY group was significantly associated with the MD slope. CONCLUSIONS: The rate of progression of the field defects, the MD slope, in patients with NTG is possibly dependent on the baseline optic disc appearance. Thus, the optic disc appearance may be useful for the management of patients with NTG.

Calpain, an intracellular cysteine protease, has been widely reported to be involved in neuronal cell death. The purpose of this study is to investigate the role of calpain activation in axonal damage-induced retinal ganglion cell (RGC) death. Twelve-week-old male calpstatin (an endogenous calpain inhibitor) knockout mice (CAST KO) and wild-type (WT) mice were used in this study. Axonal damage was induced by optic nerve crush (NC) or tubulin destruction induced by leaving a gelatin sponge soaked with vinblastine (VB), a microtubule disassembly chemical, around the optic nerve. Calpain activation was assessed by immunoblot analysis, which indirectly quantified the cleaved α-fodrin, a substrate of calpain. RGCs were retrogradely labeled by injecting a fluorescent tracer, Fluoro-Gold (FG), and the retinas were harvested and flat-mounted retinas prepared. The densities of FG-labeled RGCs harvested from the WT and CAST KO groups were assessed and compared. Additionally, a calpain inhibitor (SNJ-1945, 100 mg/kg/day) was administered orally, and the density of surviving RGCs was compared with that of the vehicle control group. The mean density of surviving RGCs in the CAST KO group was significantly lower than that observed in the WT group, both in NC and in VB. The mean density of surviving RGCs in the SNJ-1945-treated group was significantly higher than that of the control group. The calpain inhibitor SNJ-1945 has a neuroprotective effect against axonal damage-induced RGC death. This pathway may be an important therapeutic target for preventing this axonal damage-induced RGC death, including glaucoma and diabetic optic neuropathy and other CNS diseases that share a common etiology.

To investigate the potential of nanoparticles (NPs) composed of poly(γ-glutamic acid) conjugated with l-phenylalanine (γ-PGA-Phe NPs) for the treatment of retinal diseases, γ-PGA-Phe NPs (200nm) were tested with macrophages and microglia in vitro or by intravitreal administration into normal or pathological rat eyes. The anti-inflammatory effects of the NPs containing dexamethasone (DEX-NPs) were examined using qRT-PCR in vitro by counting activated microglia and Fluorogold-labeled retinal ganglion cells in the retinas under excitotoxicity or by counting TUNEL (+) photoreceptors in the detached retinas. The NPs were taken up efficiently by cultured macrophages or microglia. At day 7, 60-80% of the diffuse signal remained in the cytoplasm of these cells. In normal rat eyes, the NPs did not accumulate in the retinas and no inflammatory cells were recruited. Conversely, under pathological conditions, the NPs were localized in activated CD11b-positive cells in the retina. DEX-NPs suppressed the expression of TNFα and MCP-1 in cultured macrophages or microglia, the activation of microglia, the loss of retinal ganglion cells (RGCs) in excitotoxic retinas, and the number of TUNEL (+) photoreceptors in detached retinas. These data suggest that γ-PGA-Phe NPs can be a powerful tool for suppressing inflammatory cells in pathological conditions in the retina.

A 20-year-old woman was involved in a traffic accident while riding a motorcycle. The vision in her right eye was severely reduced. At the first examination, the eyelids of her right eye were severely swollen, and the eye could barely be seen. The fundus was not visible. She had no light perception in her vision. Computed tomography revealed a severe blow-out fracture in her right eye. Surgery was immediately performed to correct the fracture and the eye globe was replaced in the orbit. On the fourth postoperative day, the right fundus was visible and a cherry-red spot and milky-white edema were seen. Fluorescein angiography showed an arterial filling defect. Four months later, her visual acuity was light perception. Our case shows that a central retinal artery occlusion can be a complication of a blow-out fracture of the lower orbital wall and can lead to severe visual loss even with early surgical repair.